Bahraini police battled the biggest anti-government protests in weeks as tens of thousands of protesters rallied in support of Nabeel Rajab. The activist was arrested again reportedly because of posts on social networks.

However, he was released on bail. The reason for the June 6 detention was reportedly his posts on Twitter, which allegedly insulted residents of a Sunni-dominated neighborhood for its close ties with Bahrain's ruling dynasty.

Rajab has played a significant role in anti-regime demonstrations in recent months. The Bahrain Center for Human Rights has been focusing on drawing attention to the crackdowns on demonstrators and abuses by Bahrain’s security forces. Rajab is also affiliated with international groups such as Human Rights Watch.

Bahrain has been facing widespread unrest since February 2011, as the Arab Spring revolutions swept across the region. The unrest was fueled by sectarian divisions – the country's ruling family are Sunni Muslims, while 70 per cent of the population are Shiites, who are now demanding greater rights and freedoms.

Protesters in the village of Sitra, south of Manama, rally in solidarity with leading Shiite activist Nabeel Rajab on June 7, 2012. (AFP Photo / Mohammed Al-Shaikh)

AFP Photo / Mohammed Al-Shaikh

Protesters in the village of Sitra, south of Manama, rally in solidarity with leading Shiite activist Nabeel Rajab on June 7, 2012. (AFP Photo / Mohammed Al-Shaikh)

Protesters in the village of Sitra, south of Manama, rally in solidarity with leading Shiite activist Nabeel Rajab on June 7, 2012. (AFP Photo / Mohammed Al-Shaikh)

Protesters in the village of Sitra, south of Manama, rally in solidarity with leading Shiite activist Nabeel Rajab on June 7, 2012. (AFP Photo / Mohammed Al-Shaikh)

Protesters in the village of Sitra, south of Manama, rally in solidarity with leading Shiite activist Nabeel Rajab on June 7, 2012. (AFP Photo / Mohammed Al-Shaikh)